Frotz Posted April 6, 2010 Share Posted April 6, 2010 I finished replacing the electrolytic caps in my Vectrex and moved on to replacing the audio cable with coax to prevent buzzing. I'm having trouble with that part. How do you solder the coax to the underside of the logic board? The place where it needs to go is up against the on-off/volume pot. Quote Link to comment Share on other sites More sharing options...
+Mitch Posted April 6, 2010 Share Posted April 6, 2010 Which no-buzz mod are you doing? When I recapped my Vectrex I removed one wire as well to kill the buzz. Mitch Quote Link to comment Share on other sites More sharing options...
Frotz Posted April 6, 2010 Author Share Posted April 6, 2010 Which no-buzz mod are you doing? When I recapped my Vectrex I removed one wire as well to kill the buzz. Mitch The one where you also replace the audio cable running from the logic board to the power board with a length of coax. Quote Link to comment Share on other sites More sharing options...
Seob Posted April 6, 2010 Share Posted April 6, 2010 (edited) Guess this on the buzz reduction 2 part: play vectrex Look at this forum, maybe it answers your question: Amibay forum Edited April 6, 2010 by Seob Quote Link to comment Share on other sites More sharing options...
Frotz Posted April 6, 2010 Author Share Posted April 6, 2010 Guess this on the buzz reduction 2 part: play vectrex That's the one. This text is clear as mud. Let's see if I have it right... Put the center conductor of the coax in the hole on the logic board where the audio signal was (going in from the TOP). Solder the shield to the leftmost pin of the volume pot (when viewing from the rear). Solder one end of the 14ga wire to the "same node where the audio cable was connected to.". Run the coax to the rear of the logic board, underneath, then out again on the left (when viewing from the rear) to meet with the backside of the power board. Solder the coax to the power board from the back. Solder one end of the 14ga wire to the power board at the hole labeled G2. What is this node that the audio cable was connected to? The only connections I see there are the signal (to which I solder the center of the coax) and a hole that doesn't connect to anything. G2 is clearly a ground. I can't figure out where the other end of the wire needs to go. Quote Link to comment Share on other sites More sharing options...
+Mitch Posted April 6, 2010 Share Posted April 6, 2010 OK, I only did buzz reduction number 1 and it removed nearly all of the buzz for me. Mitch Quote Link to comment Share on other sites More sharing options...
lgallair Posted April 7, 2010 Share Posted April 7, 2010 The "node" is referring to one of the pins of J302 on the logic board. You'll notice one of the pins is not connected to anything; ignore this one and solder the center wire to the other pin/node. Quote Link to comment Share on other sites More sharing options...
Frotz Posted April 7, 2010 Author Share Posted April 7, 2010 I figured out the "other node" business and put the Vectrex back together. The vector is crisp and bright. The buzz is much-reduced, still present, but acceptable. One significant problem that remains is that the picture shakes, particularly in the bottom-right (right where the reserve ships are in Minestorm). According to the service guide, the likely culprits are some ceramic caps on the power board, a ceramic cap on the CRT board, and an op-amp underneath the heat sink on the power board. I'm tempted to replace all of these. Has anyone here sucessfully done repairs on the stuff underneath the heat sink? Quote Link to comment Share on other sites More sharing options...
ollie1974 Posted September 8, 2015 Share Posted September 8, 2015 (edited) I figured out the "other node" business... shame did not share the answer.. im currently in the same stuck mess u were 5 years ago (god knows what is meant by the 'node'). Edited September 8, 2015 by ollie1974 Quote Link to comment Share on other sites More sharing options...
ollie1974 Posted September 8, 2015 Share Posted September 8, 2015 (edited) if anyone knows where the 14AWG wire is supposed to go (from where, to where) please post here, thanks (that's regarding this article): http://www.playvectrex.com/vectech/quietvec/quiet_vectrex.pdf Edited September 8, 2015 by ollie1974 Quote Link to comment Share on other sites More sharing options...
ollie1974 Posted September 8, 2015 Share Posted September 8, 2015 (edited) hmm i think i will just assume that the article (Buzz Reduction #2 (Harder): means: .......to solder the 14AWG ground wire, and the Braided 'ground' shield of the new audio cable, both together (alongside each other, so in parallel), to the designated ground points of the power, and logic boards (the ground points being, G2 on the power board, and on the logic board: the leftmost pin of the volume pot* (when viewing from the rear)...... *which will be labelled R236 or R326 i'm assuming we do this (add the 14AWG wire) so there is some extra grounding going on between the power and logic boards, in case the braided wire on its own is not quite a good enough ground for the task in hand. (if anyone knows if my assumption above is incorrect, please shout, thanks!) Edited September 8, 2015 by ollie1974 Quote Link to comment Share on other sites More sharing options...
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